146 CALIFORNIA ACADEMY OF SCIENCES. [Proc. 30 Ser. 



EXPLANATION OF PLATE VIIL 



Page. 

 Placenticeras pacificum Smith. 79 



(After J. P. Smith, Proc. Cal. Acad. Sci., 3d Ser., Geol., 

 Vol. I, Plate XXV.) 

 Figs. 162-163. Four coils; diameter 20.5 mm.; X2.7. Ar- 

 royo del Vall(5, Alameda County, California. 

 Fig. 164. Four and five-sixths coils; diameter 47 mm.; 



natural size. Henley, California. 

 Pachydiscus hetileyetisis, sp. nov. 104 



Fig. 165. Section of whorl reduced, at fourteen inches. 

 Fig. 166. Section of whorl at a diameter of three and one-half 

 inches. 

 Gyrodes siskiyouensis, sp. nov. 76 



Fig. 167. Front view; natural size. 

 Fig. 168. Top view of same. 

 Belemnites, sp. Texas Flat, Shasta County, California. 40 



Fig. 169. Shell partly restored; natural size. 

 Fig. 170. Enlarged view, showing protoconch. 

 Placenticeras pacificum Smith. 79 



Figs. 171-172. Adolescent stage; two and five-sixteenths coil; 

 diameter 2.32 mm. ; Xio. Henley, California. 

 Placejiticeras cali/ortiicum, sp. nov. 78 



(After J. P. Smith, Proc. Cal. Acad. Sci., 3d Ser. Geol., 

 Vol. I, Plate XXV.) 

 Fig. 173. Three coils; diameter 8 mm.; X2.7. Henley, 



California. 

 Figs. 174-175. Adolescent stage; three and five-eighths coils; 

 diameter 14 mm. ; X2. Henley, California. 

 Figs. 176-177. Adolescent stage; four coils; diameter 22 mm.; 

 X2. Arroyo del Vall6, Alameda County, 

 California. 

 Fig. 178. Four and one-half coils; diameter 34.5 mm.; 



X2. Henley, California. 

 Anchura cotidojiiana , sp. nov. 76 



Fig- 179- Full grown shell; natural size. 



